The present invention relates to a device for mounting a developing unit which develops an electrostatic latent image formed on an image carrier in an imaging forming apparatus.
Conventionally, an image forming apparatus, such as an electrophotographic copying machine, forms an electrostatic latent image on a photoreceptor or an image carrier and develops the latent image normally with a black toner utilizing a developing unit. As the demand for monocolor development with various color tones such as blue or red toner as well as with black toner increases copying machines whose developing units are replaced according to the intended development color have been increasingly used in the recent years. As another new type of copying machine, the image forming means is supported integrally with the photoreceptor to form an image forming unit which can be removed from the copying machine. Such image forming units and copying machines adapted for these units have been already commercially produced. This type of copying machines does not require regular adjustment and replacement of the photoreceptor, charge wire used and of the waste toner container. Accordingly, maintenance is easy even for the user with no expertise.
When there are two or more units to be mounted in the copying machine mentioned above, they can be mounted in the wrong order. Mounting of the image forming unit and the developing unit in the wrong order can result in improper positioning of the developing unit with respect to the image forming unit or improper dispersion of toner from the magnetic brush of the developing unit, or in the worst case, can damage the copying machine.